Caster

ABSTRACT

The invention relates to a caster, for example, a bed caster, appliance caster, heavy-load caster or the like, which have versatile uses in the private and commercial sectors. The inventive caster has a braking device that acts upon the lateral faces of the wheel.

BACKGROUND OF THE INVENTION

The invention concerns a transport roller, such as is often used forexample as a bed roller, an apparatus roller, a heavy-load roller orsuchlike in the private and industrial sector. As a rule, the roller issteerable. Such a steering roller is shown in DE 197 24 577.

The known steering roller has a wheel, which is carried in a rotarymanner on a fixture.

On this fixture there is also arranged a brake shoe, which by means of abolt on the fixture can be pressed against the running face of the wheeland again released from the running face of the wheel.

Depending on the material type and/or material hardness of the runningface of the wheel, different forces are required to achieve a desiredbraking effect. The braking power changes with increasing wear on therunning face.

It is intended with the invention to make available a transport rollerof the initially mentioned type with an alternative braking device,whereby the braking device should in particular be ready for operationindependently of the wear on the wheel and independently of the materialof the running face of the wheel.

SUMMARY OF THE INVENTION

In its most general form of embodiment, the invention relates to atransport roller with the following features:

-   -   a wheel, which is carried in a rotary manner on a fixture,    -   a one- or multi-piece bearing block, which is fixed to the        fixture or is a component of the fixture,    -   two sections of the bearing block run outside the wheel in its        peripheral area on opposite sides of the wheel,    -   each section has a pivot bearing, on which a brake lever is        carried,    -   the brake levers are connected via a spring at their end running        above the pivot bearing in such a way that the spacing of the        brake levers at their ends is variable by means of a change in        the spring length between the linking points of the spring to        the brake levers.

In this way, a transport roller is made available with a braking devicewhich does not act on the running face of the wheel, but on the sidefaces of the wheel, in particular a wheel web, i.e. the section of thewheel which runs between the wheel hub and the wheel running face andessentially has the form of a disc with a central hole.

In this way, the braking device is independent of the type and materialof the running face. The braking device is thus also independent of thedegree of wear on the running face.

A further advantage consists in the fact that the braking device actslaterally on the wheel, where less dirt usually accumulates. The dirt ispicked up chiefly by the running face and cannot impair the operatingability of the braking device in the case of the transport rollermentioned here.

A further important aspect of the transport roller is that theassociated braking device can also be retrofitted on existing transportrollers.

This applies in particular when the spring acting upon the brake leveris itself acted upon by a bolt, which is already present for example inthe form of embodiment according to DE 197 24 577 C1 and performsvarious functions inside a steering roller.

According to one form of embodiment, the bearing block runs essentiallyparallel to the wheel axis, or in other words: normal to the runningdirection of the wheel. With a one-part bearing block, it goes withoutsaying that it has to overlap the wheel with a gap. The bearing blockcan, however, be readily designed in two parts. It is advantageous ifsections of the bearing block are present respectively on both sides ofthe wheel, to which sections the brake levers can be coupled.

The structural shape then remains small. In principle, the pivotbearings for the brake levers can also lie beside the running face ofthe wheel. The levers must then, however, be sharply curved. Thesections of the bearing block can, as vertical pins, also be a componentof the fixture for the wheel.

In order to achieve as high a degree of variability as possible inrespect of the braking power, one form of embodiment makes provisionsuch that the brake levers are designed in such a way that their armspointing away from the wheel, i.e. as a rule the arms running above thepivot bearing, are shorter than the arms lying opposite. Such a form ofembodiment is explained in greater detail in the following descriptionof the figures.

This also shows that the brake levers can be arranged structurallyidentically, but mirror-inverted inside the braking device and bent inthe direction of one another at their wheel-side (lower) end.

The “brake path” can thus be reduced, in particular in the case ofwheels with relatively wide running faces and only a disc-type wheelweb.

The sections of the brake levers important for braking can be designedwith brake linings (friction linings).

Whilst the pivot bearings for the brake levers can be simple bolts, thespring—depending on the arrangement inside the fixture—can be fitted atits ends on corresponding pins of the brake levers or be fixed in akeyed manner.

Further features of the invention and the mode of operation of thedescribed braking device emerge from the features of the subclaims aswell as the further parts of the application, in particular thefollowing description of the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

A form of embodiment of the invention is represented diagrammatically invarious views and details, i.e. in

FIG. 1: a perspective view, partially in vertical section, of atransport roller,

FIG. 2: a perspective partial view of the wheel solely with theassociated braking device,

FIG. 3: a perspective separate view of the braking device,

FIG. 4: a partial section through the transport roller according to FIG.1 in the area of its brake lever.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 shows a transport roller with a fixture 10, in which amongstother things a crown gear 12 is carried, through which a bolt (a toothedspindle) 14 reaches. A shaft 16 is also a component of fixture 10, onwhich shaft there sits a bearing which carries a wheel (running wheel)18 in a rotary manner.

Wheel 18 has a running face 18 f, on which a brake shoe acts accordingto the prior art (DE 197 24 577 C1).

The braking device according to the invention, on the other hand,includes a bearing block 20, which is fixed to fixture 10 and extendsover the lateral faces of wheel 18 at a distance from running face 18 fof wheel 18 and parallel to shaft 16, as FIGS. 1, 2 show. The twosections 20 l, 20 r of bearing block 20 running outside the wheel carrybolts 22, which run essentially horizontal and parallel to a wheel web18 s of wheel 18 carrying running face 18 f on its peripheral side.

Brake levers 24 l, 24 r are carried in a rotary manner on bolts 22. Itcan be seen from FIG. 3 in particular that the brake levers each have ashorter arm 241 o, 24 ro above bolts (rotary pivots) 22 than in thelower part (arms 24 lu, 24 ru).

Sections 24 lu, 24 ru are bent inwards (towards one another) at theirlower end and carry friction linings 26 there.

In the assembly position, but in the state of wheel 18 when the brakesare not applied, brake levers 24 l, 24 r, or more precisely their brakelinings 26, lie as a small distance in front of wheel web 18 s.

At the opposite end, i.e. in the area of sections 24 lo, 24 ro, brakelevers 24 l, 24 r are designed narrowed and in each case accommodate atransverse pin 28, on which a bent-over end of a leaf spring 30 sits ina keyed manner. Leaf spring 30 is curved in a convex manner in relationto wheel 18 and is dimensioned such that, in the unloaded state, itholds brakes 24 l, 24 r at a distance that corresponds to that describedpreviously, i.e. at which friction linings 26 stand at a distance infront of the surfaces of wheel web 18 s lying opposite.

If, in the operation, spring 30 is loaded (arrow direction P in FIG. 1)by bolt (toothed spindle) 14 represented in FIG. 1, spring 30 pushessections 24 lo, 24 ro of brake levers 24 l, 24 r apart. In parallelthereto, lower sections 24 lu, 24 ru are moved in the direction towardsone another, whereby they are conveyed towards the surfaces of wheel web18 s and brake wheel 18.

After retraction of bolt 14, the braking position of brake levers 24 l,24 r is again released, since leaf spring 30 is brought back into itsunloaded initial position and sections 24 lo, 24 ro are again movedtowards one another and sections 24 lu, 24 ru again moved away from oneanother.

1. A transport roller, comprising: a wheel (18), which is carried in arotary manner on a fixture (10); a one- or multi-piece bearing block(20), which is fixed to the fixture (10) or is a component of thefixture; two sections (20 1 , 20 r) of the bearing block (20) runoutside the wheel (18) in its peripheral area on opposite sides of thewheel (18); each section (20 l, 20 r) has a pivot bearing (22), on whicha brake lever (24 l, 24 r) is carried; and the brake levers (24 l, 24 r)are connected by a spring (30) at their end (24 lo, 24 ro) running abovethe pivot bearing (22) in such a way that a spacing of the brake levers(24 l, 24 r) at their ends (24 lo, 24 ro; 24 lu, 24 ru) is variable bymeans of a change in the spring length between the linking points of thespring (30) to the brake levers (24 l, 24 r).
 2. The transport rolleraccording to claim 1, wherein the bearing block (20) whereof runsessentially parallel to the wheel axis and overlaps the wheel (18) witha gap.
 3. The transport roller according to claim 1, wherein first arms(24 lo, 24 ro) of the brake levers (24 l, 24 r) running above the pivotbearing (22) are shorter than second arms (24 ru, 24 lu) of the brakelevers (24 l, 24 r) running below the pivot bearing (22).
 4. Thetransport roller according to claim 1, the brake levers (24 l, 24 r)whereof are coupled on the bearing block (20) in a structurallyidentical, but mirror-inverted manner.
 5. The transport roller accordingto claim 1, the brake levers (24 l, 24 r) whereof are bent in thedirection of one another at their end (24 lu, 24 ru) running below thepivot bearing (22).
 6. The transport roller according to claim 1, withwhich the ends (24 lu, 24 ru) of the brake levers (24 l, 24 r) runningbelow the pivot bearings are designed with brake linings (26).
 7. Thetransport roller according to claim 1, the pivot bearings (22) whereofconsist of bolts, whose axes run parallel to the wheel plane.
 8. Thetransport roller according to claim 1, with which the spring (30) isdesigned as a leaf spring.
 9. The transport roller according to claim 1,with which the spring (30) is bent over as it ends and fitted oncorresponding bearing pins (28).
 10. The transport roller according toclaim 1, with which the spring (30) can be acted upon by a bolt (14).11. The transport roller according to claim 10, with which the bolt (14)is a component of the fixture (10) carrying the wheel (18).